Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205 122 PPEQVILDLQPEWVAVDEAFTVTCHVPSVAPLQSLTLTLLQGDQELHRKDFLSLSLVSQRAEVTATVRAHRDNDRRNFSC 201
Cdd:cd05755    1 PPERVELTPLPSWQPVGKNFTLRCRVPGGAPRASLTLVLLRGNETLHRETFGGAAPAPQPAEATFTVLARREDHGANFSC 80

                         90       100
                 ....*....|....*....|.
gi 568976205 202 RAELDLSPHGGGLFHGSSATK 222
Cdd:cd05755   81 LAELDLRPQGLNLFHNHSAPR 101

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205 423 NQIWVEGMHQMLACIPEGNPTPVLVcvWNGMIFDL--DVPQKATQNHT-----------GTYCCTATNPLGSVSKDITII 489
Cdd:cd05731    4 STMVLRGGVLLLECIAEGLPTPDIR--WIKLGGELpkGRTKFENFNKTlkienvseadsGEYQCTASNTMGSARHTISVT 81

                 ..
gi 568976205 490 VQ 491
Cdd:cd05731   82 VE 83

Second immunoglobulin (Ig)-like C2-set domain of intercellular cell adhesion molecule 1 (ICAM-1), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of intercellular cell adhesion molecule 1 (ICAM-1; also known as domain of cluster of differentiation (CD) 54) and similar proteins. During the inflammation process, these molecules recruit leukocytes onto the vascular endothelium before extravasation to the injured tissues. ICAM-1 may be involved in organ targeted tumor metastasis. The interaction of ICAM-1 with leukocyte function-associated antigen-1 (LFA-1) plays a part in leukocyte-endothelial cell recognition. This group also contains ICAM-2 which also interacts with LFA-1. Transmigration of immature dendritic cells across resting endothelium is dependent on the interaction of ICAM-2 with, yet unidentified, ligand(s) on the dendritic cells. ICAM-1 has five Ig-like domains and ICAM-2 has two. ICAM-1 may also act as host receptor for viruses and parasites. The structures of this group show that the second Ig domain lacks a D strand and thus belonging to the C2-set of the IgSF

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205 122 PPEQVILDLQPEWVAVDEAFTVTCHVPSVAPLQSLTLTLLQGDQELHRKDFLSLSLVSQRAEVTATVRAHRDNDRRNFSC 201
Cdd:cd05755    1 PPERVELTPLPSWQPVGKNFTLRCRVPGGAPRASLTLVLLRGNETLHRETFGGAAPAPQPAEATFTVLARREDHGANFSC 80

                         90       100
                 ....*....|....*....|.
gi 568976205 202 RAELDLSPHGGGLFHGSSATK 222
Cdd:cd05755   81 LAELDLRPQGLNLFHNHSAPR 101

N-terminal immunoglobulin domain of the intercellular adhesion molecules ICAM-2 (Cluster of Differentiation 102 or CD102); member of the I-set of IgSF domains; The members here are composed of the N-terminal immunoglobulin domain of the intercellular adhesion molecules ICAM-2 (Cluster of Differentiation 102 or CD102). The intercellular adhesion molecules ICAM-1 (Cluster of Differentiation 54 or CD54), ICAM-2 and ICAM-3 (Cluster of Differentiation 50 or CD50) mediate a variety of critical intercellular adhesion events in the immune system through interactions with their counter-receptors, the beta2-integrins LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), p150,95 (CD11c/CD18), and CD11d/CD18. The ICAMs are type I transmembrane glycoproteins belonging to the immunoglobulin superfamily (IgSF). The binding of the ICAM family members with the beta2-integrins physically stabilizes interactions between pairs of T and B cells, T cells and antigen-presenting cells (APCs), and brings effector cells such as cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells into close proximity to their target cells. All three ICAMs share a common polypeptide homology and structural motif, and the ability to bind LFA-1. The distinct functional role of each ICAM is affected by their relative affinities for LFA-1 (ICAM-1 > ICAM-2 > ICAM-3). ICAM-1 is expressed in most tissues at low levels, and expression is increased by inflammatory cytokines. In contrast, ICAM-2 is expressed predominantly on endothelium and leukocytes (except neutrophils), and its expression generally is not responsive to cytokines. ICAM-3 is expressed on leukocytes and Langerhans cells, but not on resting, cytokine-induced endothelium, or nonhematopoietic tissues.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205  38 FQVSVHPNEALVEFGHSLTVNCSTTCPDPGPSGIETFLKKTQLSKGSQWKEFLLEDITEDLVLQCFFSCAGEQKDTVLAI 117
Cdd:cd20995    1 FEVYIRSEKQIVEATESWEVNCSTSCAQPEVGGLETPTNKILLEEQAQWKHYLVSNVSHDTVLLCHFTCSGKQESESFNI 80

                 ...
gi 568976205 118 TMY 120
Cdd:cd20995   81 SVY 83

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205   421 PGNQIWVEGMHQMLACIPEGNPTPVLVCVWNGMIFDLDVP---------------QKATQNHTGTYCCTATNPLGSVSKD 485
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGrfsvsrsgststltiSNVTPEDSGTYTCAATNSSGSASSG 80

                   ....*
gi 568976205   486 ITIIV 490
Cdd:smart00410  81 TTLTV 85

Second immunoglobulin (Ig)-like C2-set domain of intercellular cell adhesion molecule 1 (ICAM-1), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of intercellular cell adhesion molecule 1 (ICAM-1; also known as domain of cluster of differentiation (CD) 54) and similar proteins. During the inflammation process, these molecules recruit leukocytes onto the vascular endothelium before extravasation to the injured tissues. ICAM-1 may be involved in organ targeted tumor metastasis. The interaction of ICAM-1 with leukocyte function-associated antigen-1 (LFA-1) plays a part in leukocyte-endothelial cell recognition. This group also contains ICAM-2 which also interacts with LFA-1. Transmigration of immature dendritic cells across resting endothelium is dependent on the interaction of ICAM-2 with, yet unidentified, ligand(s) on the dendritic cells. ICAM-1 has five Ig-like domains and ICAM-2 has two. ICAM-1 may also act as host receptor for viruses and parasites. The structures of this group show that the second Ig domain lacks a D strand and thus belonging to the C2-set of the IgSF

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205 122 PPEQVILDLQPEWVAVDEAFTVTCHVPSVAPLQSLTLTLLQGDQELHRKDFLSLSLVSQRAEVTATVRAHRDNDRRNFSC 201
Cdd:cd05755    1 PPERVELTPLPSWQPVGKNFTLRCRVPGGAPRASLTLVLLRGNETLHRETFGGAAPAPQPAEATFTVLARREDHGANFSC 80

                         90       100
                 ....*....|....*....|.
gi 568976205 202 RAELDLSPHGGGLFHGSSATK 222
Cdd:cd05755   81 LAELDLRPQGLNLFHNHSAPR 101

N-terminal immunoglobulin domain of the intercellular adhesion molecules ICAM-2 (Cluster of Differentiation 102 or CD102); member of the I-set of IgSF domains; The members here are composed of the N-terminal immunoglobulin domain of the intercellular adhesion molecules ICAM-2 (Cluster of Differentiation 102 or CD102). The intercellular adhesion molecules ICAM-1 (Cluster of Differentiation 54 or CD54), ICAM-2 and ICAM-3 (Cluster of Differentiation 50 or CD50) mediate a variety of critical intercellular adhesion events in the immune system through interactions with their counter-receptors, the beta2-integrins LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), p150,95 (CD11c/CD18), and CD11d/CD18. The ICAMs are type I transmembrane glycoproteins belonging to the immunoglobulin superfamily (IgSF). The binding of the ICAM family members with the beta2-integrins physically stabilizes interactions between pairs of T and B cells, T cells and antigen-presenting cells (APCs), and brings effector cells such as cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells into close proximity to their target cells. All three ICAMs share a common polypeptide homology and structural motif, and the ability to bind LFA-1. The distinct functional role of each ICAM is affected by their relative affinities for LFA-1 (ICAM-1 > ICAM-2 > ICAM-3). ICAM-1 is expressed in most tissues at low levels, and expression is increased by inflammatory cytokines. In contrast, ICAM-2 is expressed predominantly on endothelium and leukocytes (except neutrophils), and its expression generally is not responsive to cytokines. ICAM-3 is expressed on leukocytes and Langerhans cells, but not on resting, cytokine-induced endothelium, or nonhematopoietic tissues.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205  38 FQVSVHPNEALVEFGHSLTVNCSTTCPDPGPSGIETFLKKTQLSKGSQWKEFLLEDITEDLVLQCFFSCAGEQKDTVLAI 117
Cdd:cd20995    1 FEVYIRSEKQIVEATESWEVNCSTSCAQPEVGGLETPTNKILLEEQAQWKHYLVSNVSHDTVLLCHFTCSGKQESESFNI 80

                 ...
gi 568976205 118 TMY 120
Cdd:cd20995   81 SVY 83

N-terminal immunoglobulin domain of the intercellular adhesion molecules ICAM-1 (Cluster of Differentiation 54 or CD54), ICAM-2 (CD102) and ICAM-3 (CD50); members of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain found in the N-terminus of the intercellular adhesion molecules ICAM-1 (Cluster of Differentiation 54 or CD54), ICAM-2 (CD102), and ICAM-3 (CD50). ICAM-1, ICAM-2, and ICAM-3 mediate a variety of critical intercellular adhesion events in the immune system through interactions with their counter-receptors, the beta2-integrins LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), p150,95 (CD11c/CD18), and CD11d/CD18. The ICAMs are type I transmembrane glycoproteins belonging to the immunoglobulin superfamily (IgSF). The binding of the ICAM family members with the beta2-integrins physically stabilizes interactions between pairs of T and B cells, T cells and antigen-presenting cells (APCs), and brings effector cells such as cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells into close proximity to their target cells. All three ICAMs share a common polypeptide homology and structural motif, and the ability to bind LFA-1. The distinct functional role of each ICAM is affected by their relative affinities for LFA-1 (ICAM-1 > ICAM-2 > ICAM-3). ICAM-1 is expressed in most tissues at low levels, and expression is increased by inflammatory cytokines. In contrast, ICAM-2 is expressed predominantly on endothelium and leukocytes (except neutrophils), and its expression generally is not responsive to cytokines. ICAM-3 is expressed on leukocytes and Langerhans cells, but not on resting, cytokine-induced endothelium, or nonhematopoietic tissues.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205  40 VSVHPNEALVEFGHSLTVNCSTTCPDPGPSGIETFLKKTQLSKGSQWKEFLLEDITEDLVLQCFFSCAGEQKDTVLAITM 119
Cdd:cd20944    1 TSVSPSKVILPRGGSLLVNCSTSCDQPELLGLETSLPKKLLLLPGNWKVYELSNVQEDSQPMCYSNCPGGQSTAKSNLTV 80

                 .
gi 568976205 120 Y 120
Cdd:cd20944   81 Y 81

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205 423 NQIWVEGMHQMLACIPEGNPTPVLVcvWNGMIFDL--DVPQKATQNHT-----------GTYCCTATNPLGSVSKDITII 489
Cdd:cd05731    4 STMVLRGGVLLLECIAEGLPTPDIR--WIKLGGELpkGRTKFENFNKTlkienvseadsGEYQCTASNTMGSARHTISVT 81

                 ..
gi 568976205 490 VQ 491
Cdd:cd05731   82 VE 83

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568976205  412 KPRFQESrcPGNQIWVEGMHQMLACIPEGNPTPVLVcvW---NGMIFDLDVP-------------QKATQNHTGTYCCTA 475
Cdd:pfam13927   1 KPVITVS--PSSVTVREGETVTLTCEATGSPPPTIT--WyknGEPISSGSTRsrslsgsnstltiSNVTRSDAGTYTCVA 76

                  ..
gi 568976205  476 TN 477
Cdd:pfam13927  77 SN 78